Organic Light Emitting Display Having Touch Sensor and Method of Fabricating the Same

ABSTRACT

Disclosed are an organic light emitting display having a touch sensor, which may achieve process simplification and cost reduction, and a method of fabricating the same. The organic light emitting display includes a compensation film having a flat surface and formed to cover dams forming a boundary with an organic encapsulation layer and the compensation film has a planarized surface between a region above the dams and a boundary region between the dams and the organic encapsulation layer ( 144 ) and may prevent cut and short-circuit of routing lines cutting across the same. Further, touch sensors are disposed on an encapsulation unit including the organic encapsulation layer and thus a separate attachment process is not required, thereby simplifying the overall process and reducing manufacturing costs of the organic light emitting display.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/063,456 filed on Oct. 5, 2020 which is a continuation of U.S. patentapplication Ser. No. 16/410,749 filed on May 13, 2019 which is acontinuation of U.S. patent application Ser. No. 15/621,988 filed onJun. 13, 2017 which claims the benefit of Korean Patent Application No.10-2016-0112193, filed on Aug. 31, 2016, each of which is incorporatedby reference in its entirety.

BACKGROUND Field of Technology

The present disclosure relates to an organic light emitting displayhaving a touch sensor and a method of fabricating the same, and moreparticularly, to an organic light emitting display having a touch senorwhich may achieve process simplification and cost reduction, and amethod of fabricating the same.

Discussion of the Related Art

A touchscreen is an input device through which a user may input acommand by selecting instructions displayed on a screen of a displayusing a hand or an object. That is, the touchscreen converts a contactposition directly contacting a human hand or an object into anelectrical signal and receives instructions selected at the contactposition as an input signal. Such a touchscreen may substitute for aseparate input device connected to a display and operated, such as akeyboard or a mouse, and thus applications of the touchscreen havegradually increased.

In general, a touchscreen is attached to the front surface of a displaypanel, such as a liquid crystal display panel or an organicelectroluminescent display panel, through an adhesive. In this case,since the touchscreen is separately manufactured and then attached tothe front surface of the display panel, an attachment process isadditionally carried out and thus the overall process becomescomplicated and manufacturing costs are raised.

SUMMARY

Accordingly, the present disclosure is directed to an organic lightemitting display having a touch sensor and a method of fabricating thesame that substantially obviate one or more problems due to limitationsand disadvantages of the related art.

An object of the present disclosure is to provide an organic lightemitting display having a touch sensor which may achieve processsimplification and cost reduction, and a method of fabricating the same.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

The object is solved by the features of the independent claims. Variousembodiments are given in the dependent claims.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, anorganic light emitting display includes light emitting elements disposedon an active area of a substrate, an encapsulation unit disposed on thelight emitting elements and including a plurality of inorganicencapsulation layers and at least one organic encapsulation layerdisposed between the inorganic encapsulation layers, touch sensordisposed on the encapsulation unit, dams configured to surround theactive area and to form a boundary with the at least one organicencapsulation layer, and a compensation film disposed to cover the damsand having different thicknesses between a region above the dams and aboundary region between the dams and the at least one organicencapsulation layer.

The compensation film may be realized as a stepped or staircasecompensation having different thicknesses.

A plurality of color filters may be disposed between the touch sensorand the encapsulation unit to implement light of different colors,

The compensation film is formed to have a monolayer or multilayerstructure using the same material as at least one of the color filters.

A plurality of color filters disposed between the touch sensor and theencapsulation unit to implement light of different colors.

A black matrix is disposed between the color filters.

The compensation film includes a first compensation film layer formed ofthe same material as the black matrix; and a second compensation filmlayer formed of the same material as at least one of the color filtersand disposed on the first compensation film layer.

A plurality of color filters is disposed between the touch sensor andthe encapsulation unit to implement light of different colors; a blackmatrix disposed between the color filters; and a touch buffer filmdisposed between the color filters and the touch sensor, wherein thecompensation film includes: a first compensation film layer formed ofthe same material as the black matrix; a second compensation film layerformed of the same material as at least one of the color filters anddisposed on the first compensation film layer; and a third compensationfilm layer formed of the same material as the touch buffer film anddisposed on the second compensation film layer.

A touch buffer film is disposed between the touch sensor and theencapsulation unit, wherein the compensation film is formed of the samematerial as the touch buffer film and is integrated with the touchbuffer film.

The touch buffer film is formed of any one of acryl-based, epoxy-basedand silane-based organic insulating materials.

A thickness of the compensation film in the region above the dams isless than a thickness of the compensation film in the boundary region.

Routing lines are connected to the touch sensor and intersecting oroverlapping the dams with the compensation film interposed therebetween.

The routing lines are disposed in the boundary region and in the regionabove the dams being horizontally parallel with the boundary region.

Thin film transistors are connected to the light emitting elements.

A planarization film is disposed to cover the thin film transistors,wherein the routing lines are disposed in the region above the dams aredisposed at a position higher than the upper surface of theplanarization film.

The routing line covers a side surface of the compensation film.

The touch sensor includes a touch sensing line and a touch driving lineintersecting each other

The touch driving line comprises first touch electrodes connected to oneanother through a first bridge,

The touch sensing line comprises second touch electrodes connected toone another through a second bridge.

At least one of the first and second touch electrodes comprises: a meshmetal layer have a mesh shaped pattern; and a transparent conductivelayer located on or under the mesh metal layer.

At least one of the first and second bridges comprises a slit.

The slit of the at least one of the first and second bridges overlapswith the other one of the first and second bridges.

In another aspect of the disclosure an organic light emitting display isprovided, comprising: light emitting elements disposed on an active areaof a substrate; an encapsulation unit disposed on the light emittingelements and including at least one inorganic encapsulation layer and atleast one organic encapsulation layer; a touch sensor disposed on theencapsulation unit; dams surrounding the active area and to form aboundary for the at least one organic encapsulation layer; acompensation film covering the dams, wherein the compensation film isprovided between a touch pad and the at least one organic encapsulationlayer and have different thicknesses in a region above the dams and in aboundary region between the dams and the at least one organicencapsulation layer.

The at least one inorganic encapsulation layer is provided on at leastone of the dams.

The at least one inorganic encapsulation layer is contacting aprotective film disposed on the substrate at least in the boundaryregion between the dams and the at least one organic encapsulationlayer.

A touch protective film may cover the touch sensor.

The touch protective film is formed of one of an organic insulatingmaterial, a circularly polarizing plate, or a film formed of epoxy oracryl.

The routing lines are disposed in the boundary region and in the regionabove the dams on the same horizontal level.

A portion of the routing lines comprises a first and a second layer.

At least a portion of the first layer of the routing lines is covered bya pad cover electrode.

At least a portion of the first layer of the routing lines is made ofthe same material as one of the first and second bridges.

The pad cover electrode is made of the same material as the at least onetouch electrode.

At least one of the first and second bridges is located corresponding toa bank for defining pixel areas.

The object is also solved by a method of fabricating an organic lightemitting display comprising: forming light emitting elements disposed onan active area of a substrate and dams surrounding the active area;forming an encapsulation unit disposed on the light emitting elementsand including a plurality of inorganic encapsulation layers and at leastone organic encapsulation layer disposed between the inorganicencapsulation layers to form a boundary with the dams; forming acompensation film disposed to cover the dams and having differentthicknesses between a region above the dams and a boundary regionbetween the dams and the at least one organic encapsulation layer; andforming touch sensor disposed on the encapsulation unit.

The method further comprises forming a plurality of color filtersdisposed between the touch sensor and the encapsulation unit toimplement light of different colors, wherein the compensation film isformed to have a monolayer or multilayer structure using the samematerial as at least one of the color filters.

The method further comprises forming a plurality of color filtersdisposed between the touch sensor and the encapsulation unit toimplement light of different colors; and forming a black matrix disposedbetween the color filters, wherein the compensation film includes: afirst compensation film layer formed of the same material as the blackmatrix; and a second compensation film layer formed of the same materialas at least one of the color filters and disposed on the firstcompensation film layer.

The method further comprises forming a plurality of color filtersdisposed between the touch sensor and the encapsulation unit toimplement light of different colors, forming a black matrix disposedbetween the color filters; and forming a touch buffer film disposedbetween the color filters and the touch sensor, wherein the compensationfilm includes: a first compensation film layer formed of the samematerial as the black matrix; a second compensation film layer formed ofthe same material as at least one of the color filters and disposed onthe first compensation film layer; and a third compensation film layerformed of the same material as the touch buffer film and disposed on thesecond compensation film layer.

The method further comprises forming a touch buffer film disposedbetween the touch sensor and the encapsulation unit, wherein thecompensation film is formed of the same material as the touch bufferfilm and is integrated with the touch buffer film.

The method further comprises forming routing lines connected to thetouch sensor and intersecting the dams with the compensation filminterposed there between, wherein the routing lines are disposed in theboundary region and in the region above the dams being horizontallyparallel with the boundary region.

The method further comprises forming thin film transistors connected tothe light emitting elements; and forming a planarization film disposedto cover the thin film transistors, wherein the routing lines disposedin the region above the dams are disposed at a position higher than theupper surface of the planarization film.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a plan view of an organic light emitting display having atouch sensor in accordance with one embodiment of the presentdisclosure;

FIG. 2 is a perspective view illustrating an active area shown in FIG. 1in accordance with one embodiment;

FIG. 3 is a plan view illustrating elements disposed in the active areaand a pad area shown in FIG. 1 in accordance with one embodiment;

FIG. 4 is a cross-sectional view of the organic light emitting display,taken along line I-I′ of FIG. 3 in accordance with one embodiment;

FIGS. 5A to 5C are views comparatively illustrating comparative exampleswithout a compensation film and a test example with a compensation filmin accordance with one embodiment;

FIGS. 6A to 6E are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 3 and 4in accordance with one embodiment;

FIG. 7 is a cross-sectional view illustrating an organic light emittingdisplay in accordance with a further embodiment of the presentdisclosure;

FIG. 8 is a cross-sectional view illustrating an organic light emittingdisplay in accordance with another embodiment of the present disclosure;and

FIG. 9 is a cross-sectional view illustrating an organic light emittingdisplay in accordance with yet another embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

FIGS. 1 and 2 are plan and cross-sectional views of an organic lightemitting display having a touch sensor in accordance with one embodimentof the present disclosure.

The organic light emitting display shown in FIGS. 1 and 2 has an activearea AA and a pad area PA.

The active area AA senses whether or not user touch occurs and a touchposition by sensing change in mutual capacitance Cm due to the usertouch during a touch period through touch electrodes 152 e and 154 eshown in FIG. 3 . Further, the active area AA displays an image throughunit pixels including light emitting elements. The unit pixel includesred (R), green (G) and blue (B) sub-pixels PXL, or includes red (R),green (G), blue (B), and white (W) sub-pixels PXL.

Therefore, the active area AA includes, as exemplarily shown in FIG. 2 ,a plurality of sub-pixels PXL arranged in a matrix on a substrate 111,an encapsulation unit 140 disposed on the sub-pixels PXL, a touch bufferfilm 166 disposed on the encapsulation unit 140, and mutual capacitancesCm disposed on the touch buffer film 166.

Each of the sub-pixels PXL includes a pixel driving circuit and a lightemitting element 120 connected to the pixel driving circuit.

The pixel driving circuit includes a switching thin film transistor T1,a driving thin film transistor T2 and a storage capacitor Cst.

When a scan pulse is supplied to a scan line SL, the switching thin filmtransistor T1 is turned on and thus supplies a data signal supplied to adata line DL to the storage capacitor Cst and a gate electrode of thedriving thin film transistor T2.

The driving thin film transistor T2 controls current I supplied from ahigh voltage power VDD line to the light emitting element 120 inresponse to the data signal supplied to the gate electrode of thedriving thin film transistor T2, thus adjusting the amount of lightemitted from the light emitting element 120. Further, even if theswitching thin film transistor T1 is turned off, the driving thin filmtransistor T2 supplies regular current I by voltage charging the storagecapacitor Cst until a data signal of a next frame is supplied and, thus,the light emitting element 120 maintains light emission.

Such a driving thin film transistor 130 (T2) includes, as exemplarilyshown in FIG. 4 , a gate electrode 132, a semiconductor layer 134overlapping the gate electrode 132 with a gate insulating film 112interposed there between, and source and drain electrodes 136 and 138formed on a protective film 114 and contacting the semiconductor layer134.

The light emitting element 120 includes an anode 122, an organic lightemitting layer 124 formed on the anode 122, and a cathode 126 formed onthe organic light emitting layer 124.

The anode 122 is conductively connected to the drain electrode 138 ofthe driving thin film transistor 130 (T2) exposed through a pixelcontact hole formed through a planarization film 116. The organic lightemitting layer 124 is formed on the anode 122 in an emission regionprovided by a bank 128. The organic light emitting layer 124 is formedby stacking a hole-related layer, a light emitting layer and anelectron-related layer on the anode 122 in regular order or in reverseorder. The cathode 126 is formed to be opposite the anode 122 with theorganic light emitting layer 124 interposed there between.

The encapsulation unit 140 prevents external moisture or oxygen frompenetrating through the light emitting element 120, which is vulnerableto external moisture or oxygen. For this purpose, the encapsulation unit140 includes a plurality of inorganic encapsulation layers 142 and 146and an organic encapsulation layer 144 disposed between the inorganicencapsulation layers 142 and 146, and the inorganic encapsulation layer146 is disposed as the uppermost layer. Here, the encapsulation unit 140includes at least two inorganic encapsulation layers 142 and 146 and atleast one organic encapsulation layer 144. In the present disclosure,the structure of the encapsulation unit 140 in which the organicencapsulation layer 144 is disposed between the first and secondinorganic encapsulation layers 142 and 146 will be exemplarilydescribed.

The first inorganic encapsulation layer 142 is formed on the substrate111 provided with the cathode 126 to be located most adjacent to thelight emitting element 120. Such a first inorganic encapsulation layer142 is formed of an inorganic insulating material which may be depositedat a low temperature, such as silicon nitride (SiNx), silicon oxide(SiOx), silicon oxynitride (SiON) or aluminum oxide (Al2O3). Since thefirst inorganic encapsulation layer 142 is deposited at a lowtemperature, damage to the organic light emitting layer 124, which isvulnerable to a high-temperature atmosphere, during a deposition processof the first inorganic encapsulation layer 142 may be prevented.

The organic encapsulation layer 144 is formed to have a smaller areathan that of the first inorganic encapsulation layer 142 to expose bothends of the first inorganic encapsulation layer 142. The organicencapsulation layer 144 serves as a buffer to damp stress betweenrespective layers according to bending of the organic light emittingdisplay and strengthens planarization performance of the organic lightemitting display. The organic encapsulation layer 144 is formed of anorganic insulating material, such as acrylic resin, epoxy resin,polyimide, polyethylene or silicon oxycarbide (SiOC).

If the organic encapsulation layer 144 is formed through an inkjetmethod, a plurality of dams 160 disposed in parallel between the padarea PA and the active area AA is formed. For example, the dams 160includes a first dam 162 adjacent to the pad area PA, in which touchsensing pads 180 and touch driving pads 170 are formed, and a second dam164 adjacent to the active area AA. The dams 160 serve to prevent theorganic encapsulation layer 144 in a liquid state from invading the padarea PA, when the organic encapsulation layer 144 in the liquid state isdisposed in the active area AA. Each of the first and second dams 162and 164 is formed to have a monolayer or multilayer structure. Forexample, each of the first and second dams 162 and 164 is formed of thesame material as at least one of the banks 128 and spacers (not shown)simultaneously therewith and, thus, no additional mask process may berequired and cost increase may be prevented.

The second inorganic encapsulation layer 146 is formed on the substrate111 provided with the organic encapsulation layer 144 formed thereon tocover the upper and side surfaces of the organic encapsulation layer 144and the first organic encapsulation layer 142. Therefore, the secondinorganic encapsulation layer 146 minimizes or blocks penetration ofexternal moisture or oxygen into the first inorganic encapsulation layer142 and the organic encapsulation layer 144. Such a second inorganicencapsulation layer 146 is formed of an inorganic insulating material,such as silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride(SiON) or aluminum oxide (Al2O3).

The touch buffer film 166 is disposed on the encapsulation unit 140. Thetouch buffer film 166 is formed between each of touch sensing lines 154and touch driving lines 152 and the light emitting element 120 and thusmaintains a separation distance of at least 5 μm between each of thetouch sensing lines 154 and the touch driving lines 152 and the cathode126. Therefore, capacitance of a parasitic capacitor between each of thetouch sensing lines 154 and the touch driving lines 152 and the cathode126 may be minimized and, thus, mutual influences between each of thetouch sensing lines 154 and the touch driving lines 152 and the cathode126 due to coupling there between may be prevented. If the separationdistance between each of the touch sensing lines 154 and the touchdriving lines 152 and the cathode 126 is less than 5 μm, touchperformance is lowered by mutual influences between each of the touchsensing lines 154 and the touch driving lines 152 and the cathode 126due to coupling there between.

Further, the touch buffer film 166 may prevent a liquid chemical (adeveloping solution or an etching solution), used during a process ofmanufacturing the touch sensing lines 154 and the touch driving lines152 disposed on the touch buffer film 166, or moisture from the outsidefrom invading the organic light emitting layer 124. Therefore, the touchbuffer film 166 may prevent damage to the organic light emitting layer124, which is vulnerable to the liquid chemical or moisture.

The touch buffer film 166 may be formed of an organic insulatingmaterial, which is formable at a low temperature of 100° C. or lower andhas a low dielectric constant of 1 to 3, to prevent damage to theorganic light emitting layer 124, which is vulnerable to hightemperature. For example, the touch buffer film 166 may be formed of anacryl-based, epoxy-based or siloxane-based material. The touch bufferfilm 166 formed of an organic insulating material and havingplanarization performance may prevent breakage of the touch sensinglines 154 and the touch driving lines 152 formed on the touch bufferfilm 166 and damage to the respective encapsulation layers 142, 144 and146 of the encapsulation unit 140 due to warpage of the organic lightemitting display.

The touch sensing lines 154 and the touch driving lines 152 are disposedon the touch buffer film 166 to intersect each other with a touchinsulating film 168 interposed there between.

The touch driving line 152 includes a plurality of first touchelectrodes 152 e, and first bridges 152 b to conductively connect thefirst touch electrodes 152 e.

The first touch electrodes 152 e are spaced apart from each other in theY-axis direction on the touch insulating film 168. Each of the firsttouch electrodes 152 e is conductively connected to the adjacent firsttouch electrode 152 e through the first bridge 152 b.

The first bridges 152 b are formed on the touch buffer film 166, exposedthrough touch contact holes 150 formed through the touch insulating film168, and conductively connected to the first touch electrodes 152 e. Thefirst bridge 152 b is disposed to overlap the bank 128 and, thus,lowering of an aperture ratio due to the first bridges 152 b may beprevented.

The touch sensing line 154 includes a plurality of second touchelectrodes 154 e, and second bridges 154 b to conductively connect thesecond touch electrodes 154 e.

The second touch electrodes 154 e are spaced apart from each other inthe X-axis direction on the touch insulating film 168. Each of thesecond touch electrodes 154 e is conductively connected to the adjacentsecond touch electrode 154 e through the second bridge 154 b.

The second bridges 154 b are disposed on the touch insulating film 168which is coplanar with the second touch electrodes 154 e and thus areconductively connected to the second touch electrodes 154 e withoutseparate contact holes. In the same manner as the first bridge 152 b,the second bridge 154 b is disposed to overlap the bank 128 and, thus,lowering of an aperture ratio due to the second bridges 154 b may beprevented.

Since the touch sensing lines 154 and the touch driving lines 152intersect each other with the touch insulating film 168 interposed therebetween, mutual capacitances Cm are formed at the intersections betweenthe touch sensing lines 154 and the touch driving lines 152. Therefore,the mutual capacitance Cm is charged with charges by a touch drivingpulse supplied from the touch driving line 152 and discharges thecharges to the touch sensing line 154, thus serving as a touch sensor.

The touch driving lines 152 of the present disclosure are connected to atouch driving unit (not shown) through first routing lines 156 and thetouch driving pads 170. Further, the touch sensing lines 154 areconnected to the touch driving unit through second routing lines 186 andthe touch sensing pads 180.

Each of the touch driving pads 170 and the touch sensing pads 180respectively includes a pad electrode 172 or 182 and a pad coverelectrode 174 or 184 disposed on the pad electrode 172 or 182 to coverthe pad electrode 172 or 182.

The pad electrodes 172 and 182 extend from the first and second routinglines 156 and 186. Therefore, the pad electrodes 172 and 182 of thetouch driving pads 170 and the touch sensing pads 180 are formed of afirst conductive layer which is the same material as the first andsecond routing lines 156 and 186. Here, the first conductive layer isformed to have a monolayer structure or a multilayer structure usingmetals having high corrosion resistance and high acid resistance, suchas aluminum (Al), titanium (Ti), copper (Cu) and molybdenum (Mo). Forexample, the first conductive layer has a tri-layer structure, such asTi/Al/Ti or Mo/Al/Mo.

The pad cover electrodes 174 and 184 are formed of a second conductivelayer which is the same material as the first and second touchelectrodes 152 e and 154 e. Here, the second conductive layer is atransparent conductive layer having high corrosion resistance and highacid resistance, such as ITO or IZO. The pad cover electrodes 174 and184 are exposed by a touch protective film 176, thus being connected toa signal transmission film on which the touch driving unit is mounted.Here, the touch protective film 176 is formed to cover the touch sensinglines 154 and the touch driving lines 152, thus preventing the touchsensing lines 154 and the touch driving lines 152 from being corroded byexternal moisture, etc. The touch protective film 176 is a film formedof an organic insulating material, a circularly polarizing plate, or afilm formed of epoxy or acryl.

The first routing line 156 is conductively connected to the first touchelectrode 152 e through a first routing contact hole 158 and, thus,transmits a touch driving pulse from the touch driving pad 170 to thetouch driving line 152. The second routing line 186 is conductivelyconnected to the second touch electrode 154 e through a second routingcontact hole 188 and, thus, transmits a touch signal from the touchsensing line 154 to the touch sensing pad 180. Here, the first routingline 156 extends from the first touch electrode 152 e in at least one ofthe upward direction and the downward direction of the active area andis connected to the touch driving pad 170, and the second routing line186 extends from the second touch electrode 154 e in at least one of theleftward direction and the rightward direction of the active area and isconnected to the touch sensing pad 180. Such dispositions of the firstand second routing lines 156 and 186 may be variously modified accordingto design specifications of the display.

The first and second routing lines 156 and 186 are formed on acompensation film 196 to cut across the dams 160. The first and secondrouting lines 156 and 186 cover the side surface of the compensationfilm 196. The side surface might be inclined. The compensation film 196is formed integrally with the touch buffer film 166 and is formed of thesame material as the touch buffer film 166. For example, thecompensation film 196 is formed of an acryl-based, epoxy-based orsiloxane-based organic insulating material having high planarizationperformance.

The compensation film 196 formed of an organic insulating materialhaving high planarization performance is formed to have differentthicknesses between a region above the dams 160 and a boundary regionbetween the dams 160 and the organic encapsulation layer 144. That is,the thickness d1 of the compensation film 196 in the region above thedams 160 is less than the thickness d2 of the compensation film 196 inthe boundary region between the dams 160 and the organic encapsulationlayer 144 and, thus, the compensation film 196 has a planarized surfacein the region above the dams 160 and in the boundary region between thedams 160 and the organic encapsulation layer 144. In this case, therouting line disposed on the compensation film 196 in the region abovethe dams 160 is disposed at a higher position than that of the uppersurface of the planarization film 116 disposed to cover the driving thinfilm transistor 130 (T2) and, thus, the routing line is disposed in theboundary region and the region above the dams 160 in parallel or on thesame level as in the boundary region. Therefore, the routing linedisposed above the planarization film 116 and the routing line disposedabove the dams 160 are substantially formed in parallel with each otherand, thus, cut or short-circuit of each of the first and second routinglines 156 and 186 cutting across the dams 160 may be prevented.Therefore, comparative examples in which no compensation film 196 isprovided and a test example in which a compensation film 196 is providedwill be comparatively described with reference to FIGS. 5A to 5C.

That is, in case of the comparative examples in which there is nocompensation film 196 covering dams 160, as exemplarily shown in FIGS.5A and 5B, short-circuit between the adjacent routing lines 156 and 186occurs or the routing lines 156 and 186 are cut. In more detail, after afirst conductive layer 108 is deposited on the entire surface of asubstrate 111, on which a second inorganic encapsulation layer 146 isformed to cover the dams 160, a photoresist in a liquid state is coatedon the first conductive layer 108. Here, a thickness T2 of thephotoresist formed in a region between the side surface of the dam 160and the substrate 111 is greater than a thickness T1 of the photoresistformed in a region above the dam 160. The photoresist is exposed tolight through a photo mask 100 provided with a light shielding layer102.

Here, if a light exposure dose is determined based on the thickness T1of the photoresist formed in the region above the dam 160, thephotoresist having the thickness T2 greater than the thickness T1 andformed in the region between the side surface of the dam 160 and thesubstrate 111, is not effectively exposed to light and, thus, after adeveloping process, a residual layer 106 a remains. If the firstconductive layer 108 is etched using a photoresist pattern 106 b havingsuch a residual layer 106 a, the first conductive layer 108 remains in aregion corresponding to the residual layer 106 a and thus the adjacentrouting lines 156 and 186 are short-circuited.

Further, if the light exposure dose is determined based on the thicknessT2 of the photoresist formed in the region between the side surface ofthe dam 160 and the substrate 111, the photoresist having the thinthickness T1 is excessively exposed to light and, thus, after thedeveloping process, a photoresist pattern 106 b having a line width lessthan a desired design value is formed. If the first conductive layer 108is etched using such a photoresist pattern 106 b as a mask, the linewidth of the routing lines 156 and 186 is smaller than a line width Lcorresponding to a design value or the routing lines 156 and 186 arecut, as exemplarily shown in FIG. 5B.

On the other hand, in the test example in which there is a compensationfilm 196 covering dams 160, as exemplarily shown in FIG. 5C,short-circuit between the adjacent routing lines 156 and 186 or cut ofeach of the routing lines 156 and 186 may be prevented. In more detail,after a first conductive layer 108 is deposited on the entire surface ofa substrate 111, on which a second inorganic encapsulation layer 146 anda compensation film 196 are formed to cover the dams 160, a photoresist106 in a liquid state is coated on the first conductive layer 108. Here,the photoresist 106 formed on the first conductive layer 108 has auniform thickness regardless of positions due to the compensation film196. By executing light exposure and development of the photoresist 106using a photo mask 100 provided with a light shielding layer 102, aphotoresist pattern 106 b having the same thickness throughout allregions of the substrate 111 is formed. When the first conductive layer108 is patterned through an etching process using the photoresistpattern 106 b as a mask, routing lines 156 and 186 having a line widthcorresponding to a desired design value are formed.

As described above, in the organic light emitting display having a touchsensor in accordance with this embodiment of the present disclosure, thecompensation film 196 having a flat surface is formed to cover the dams160 and thus minimizes a part generated by the dams 160, thereby beingcapable of preventing short-circuit or cut of the routing lines 156 and186. Further, while, in a conventional organic light emitting display, atouchscreen is attached to a display panel through an adhesive, in theorganic light emitting display in accordance with the presentdisclosure, the touch electrodes 152 e and 154 e are disposed on theencapsulation unit 140, a separate attachment process is omitted and,thus, process simplification and cost reduction may be achieved.

FIGS. 6A to 6E are plan and cross-sectional views illustrating a methodof fabricating the organic light emitting display shown in FIGS. 3 and 4in accordance with one embodiment.

With reference to FIG. 6A, the touch buffer film 166 and thecompensation film 196 are formed on the substrate 111 provided with theswitching thin film transistors, the driving thin film transistors 130,the anodes 122, the organic light emitting layer 124, the cathodes 126,the dams 160 and the encapsulation unit 140 formed thereon.

In more detail, the touch buffer layer 166 and the compensation film 196are simultaneously formed by applying an organic insulating material tothe substrate 111 provided with the switching thin film transistors, thedriving thin film transistors 130, the anodes 122, the organic lightemitting layer 124, the cathodes 126, the dams 160 and the encapsulationunit 140 formed thereon, and then patterning the organic insulatingmaterial through a photolithography process and an etching process usinga first mask.

Thereafter, with reference to FIG. 6B, the first bridges 152 b, the padelectrodes 172 and 182 and the first and second routing lines 156 and186 are formed on the substrate 111 provided with the touch buffer film166 and the compensation film 196 formed thereon.

In more detail, a first conductive layer is deposited on the substrate111 provided with the touch buffer film 166 and the compensation film196 formed thereon and is then patterned through a photolithographyprocess and an etching process using a second mask. Thereby, the firstbridges 152 b, the pad electrodes 172 and 182 and the first and secondrouting lines 156 and 186 are formed on the substrate 111 provided withthe touch buffer film 166 and the compensation film 196 formed thereon.

With reference to FIG. 6C, the touch insulating film 168 provided withthe touch contact holes 150 and the routing contact holes 158 is formedon the substrate 111 provided with the first bridge 152 b, the padelectrodes 172 and 182 and the first and second routing lines 156 and186.

In more detail, the touch insulating film 168 is formed by applying aninorganic insulating material or an organic insulating material to theentire surface of the substrate 111 provided with the first bridges 152b, the pad electrodes 172 and 182 and the first and second routing lines156 and 186. Here, the touch insulating film 168 uses an inorganicinsulating material, such as SiNx, SiON or SiO2, or a photoacryl-based,parylene-based or siloxane-based organic insulating material.Thereafter, the touch insulating film 168 is patterned through aphotolithography process and an etching process using a third mask, thusforming the touch contact holes 150 and the routing contact holes 158.

With reference to FIG. 6D, the pad cover electrodes 174 and 184, thefirst and second touch electrodes 152 e and 154 e and the second bridges154 b are formed on the substrate 111 provided with the touch insulatingfilm 168 having the touch contact holes 150 and the routing contactholes 158.

In more detail, a second conductive layer is deposited on the substrate111 provided with the touch insulating film 168 having the touch contactholes 150 and the routing contact holes 158 and is then patternedthrough a photolithography process and an etching process using a fourthmask, thereby forming the pad cover electrodes 174 and 184, the firstand second touch electrodes 152 e and 154 e and the second bridges 154b.

With reference to FIG. 6E, the touch protective film 176 is formed onthe substrate 111 provided with the pad cover electrodes 174 and 184,the first and second touch electrodes 152 e and 154 e and the secondbridges 154 b.

In more detail, an organic insulating material is applied to the entiresurface of the substrate 111 provided with the pad cover electrodes 174and 184, the first and second touch electrodes 152 e and 154 e and thesecond bridges 154 b. Thereafter, the organic insulating material ispatterned through a photolithography process and an etching processusing a fifth mask, thereby forming the touch protective film 176exposing the touch driving pads 170 and the touch sensing pads 180.

FIG. 7 is a cross-sectional view illustrating an organic light emittingdisplay in accordance with a further embodiment of the presentdisclosure.

The organic light emitting display shown in FIG. 7 is the same as theorganic light emitting display shown in FIGS. 3 and 4 , except that acompensation film 196 is formed to have a multilayer structure formed ofthe same materials as color filters 192. Therefore, a detaileddescription of elements of the organic light emitting display shown inFIG. 7 , which are substantially the same as those of the organic lightemitting display shown in FIGS. 3 and 4 , will be omitted because it isconsidered to be unnecessary.

The color filters 192 are formed on an encapsulation unit 140 in anactive area. Therefore, white light generated by light emitting elements120 is emitted through the color filters 192, thus forming an image.

Further, the color filters 192 together with the touch buffer film 166are formed between each of touch sensing lines 154 and touch drivinglines 152 and the light emitting element 120. A separation distancebetween each of the touch sensing lines 154 and the touch driving lines152 and the light emitting element 120 is increased by the color filters192 and the touch buffer film 166. Therefore, capacitance of a parasiticcapacitor between each of the touch sensing lines 154 and the touchdriving lines 152 and the light emitting element 120 may be minimizedand, thus, mutual influences between each of the touch sensing lines 154and the touch driving lines 152 and the light emitting element 120 dueto coupling there between may be prevented. Further, the touch bufferfilm 166 and the color filters 192 may prevent a liquid chemical (adeveloping solution or an etching solution), used during a process ofmanufacturing the touch sensing lines 154 and the touch driving lines152 disposed on the touch buffer film 166, or moisture from the outsidefrom invading an organic light emitting layer 124. Therefore, the touchbuffer film 166 and the color filters 192 may prevent damage to theorganic light emitting layer 124, which is vulnerable to the liquidchemical or moisture.

The compensation film 196 is formed to have a multilayer structure, andat least one layer of the compensation film 196 is formed of the samematerial as at least one of red, green and blue color filters 192. Forexample, the compensation film 196 has a tri-layer structure, and twoout of the three layers of the compensation film 196 are formed of thesame material as the color filters 192.

A first compensation film layer 196 a is formed of the same material asany one of the red (R), green (G) and blue (B) color filters 192 tocover the dams 160. Here, a thickness of the first compensation filmlayer 196 a in a region above the dams 160 is less than a thickness ofthe first compensation film layer 196 a in a boundary region between thedams 160 and the organic encapsulation layer 144 and, thus, the firstcompensation film layer 196 a has a planarized surface between theregion above the dams 160 and the boundary region between the dams 160and the organic encapsulation layer 144.

A second compensation film layer 196 b, which is formed of the samematerial as the color filter 192 emitting colored light differing fromthe color filter 192 formed of the same material as the firstcompensation film layer 196 a, is formed on the first compensation filmlayer 196 a.

A third compensation film layer 196 c, which is formed of the samematerial as the touch buffer film 166, is formed on the secondcompensation film layer 196 b to be integrated with the touch bufferfilm 166.

The compensation film 196 compensates for a height difference generatedbetween the region above the dams 160 and the boundary region and maythus prevent cut or short-circuit of the first and second routing lines156 and 186 cutting across the dams 160.

As described above, in the organic light emitting display having a touchsensor in accordance with this embodiment of the present disclosure, thecompensation film 196 having a flat surface is formed to cover the dams160 and thus minimizes a part generated by the dams 160, thereby beingcapable of preventing cut or short-circuit of the routing lines 156 and186. Further, while, in a conventional organic light emitting display, atouchscreen is attached to a display panel through an adhesive, in theorganic light emitting display in accordance with the present invention,the touch electrodes 152 e and 154 e are disposed on the encapsulationunit 140, a separate attachment process is omitted and, thus, processsimplification and cost reduction may be achieved.

Although this embodiment describes the color filters 192 as beingdisposed on the encapsulation unit 140, the color filters 192 may bedisposed on the touch buffer film 166. In this case, the firstcompensation film layer 196 a is formed of the same material as thetouch buffer film 166 and the second and third compensation film layers196 b and 196 c are formed of the same materials as the color filters192.

FIG. 8 is a cross-sectional view illustrating an organic light emittingdisplay in accordance with another embodiment of the present invention.

The organic light emitting display shown in FIG. 8 is the same as theorganic light emitting display shown in FIGS. 3 and 4 , except that acompensation film 196 is formed to have a multilayer structurerespectively formed of the same materials as color filters 192 and ablack matrix 194. Therefore, a detailed description of elements of theorganic light emitting display shown in FIG. 8 , which are substantiallythe same as those of the organic light emitting display shown in FIGS. 3and 4 , will be omitted because it is considered to be unnecessary.

The color filters 192 are formed on an encapsulation unit 140 in anactive area. Therefore, white light generated by light emitting elements120 is emitted through the color filters 192, thus forming an image.

The black matrix 194 is formed in a light shielding region betweenrespective sub-pixel regions and serves to discriminate the respectivesub-pixel regions and to prevent optical coherence and light leakagebetween the adjacent sub-pixel regions. The black matrix 194 is formedof a high-resistance black insulating material or is formed by stackingat least two of red (R), green (G) and blue (B) color filters 192.

The compensation film 196 is formed to have a multilayer structure, andat least one layer of the compensation film 196 is formed of the sameorganic insulating material as at least one of the red, green and bluecolor filters 192 and at least another layer of the compensation film196 is formed of the same organic insulating material as the blackmatrix 194.

For example, the compensation film 196 layer has a structure in whichfirst to third compensation film layers 196 a, 196 b and 196 c arestacked.

The first compensation film layer 196 a is formed of the same materialas the black matrix 194 to cover dams 160. Here, a thickness of thefirst compensation film layer 196 a in a region above the dams 160 isless than a thickness of the first compensation film layer 196 a in aboundary region between the dams 160 and the organic encapsulation layer144 and, thus, the first compensation film layer 196 a has a planarizedsurface between the region above the dams 160 and the boundary regionbetween the dams 160 and the organic encapsulation layer 144.

The second compensation film layer 196 b, which is formed of the samematerial as the color filter 192, is formed on the first compensationfilm layer 196 a.

The third compensation film layer 196 c, which is formed of the samematerial as the touch buffer film 166, is formed on the secondcompensation film layer 196 b to be integrated with the touch bufferfilm 166.

The compensation film 196 compensates for a height difference generatedbetween the region above the dams 160 and the boundary region and maythus prevent cut or short-circuit of the first and second routing lines156 and 186 cutting across the dams 160.

As described above, in the organic light emitting display having a touchsensor in accordance with this embodiment of the present invention, thecompensation film 196 having a flat surface is formed to cover the dams160 and thus minimizes a part generated by the dams 160, thereby beingcapable of preventing cut or short-circuit of the routing lines 156 and186. Further, while, in a conventional organic light emitting display, atouchscreen is attached to a display panel through an adhesive, in theorganic light emitting display in accordance with the present invention,the touch electrodes 152 e and 154 e are disposed on the encapsulationunit 140, a separate attachment process is omitted and, thus, processsimplification and cost reduction may be achieved.

Although these embodiments shown in FIGS. 7 and 8 describe that theheight difference generated due to the dams 160 is compensated for bythe first or second compensation film layer 196 a or 196 b formed of thesame material as at least one of the color filters 192 and the blackmatrix 194 and the third compensation film layer 196 c formed of thesame material as the touch buffer film 166, the generated due to thedams 160 may be compensated for only by the first or second compensationfilm layer 196 a or 196 b formed of the same material as at least one ofthe color filters 192 and the black matrix 194 without the thirdcompensation film layer 196 c formed of the same material as the touchbuffer film 166.

Further, although FIG. 4 illustrates the first and second routing lines156 and 186 as being formed to have a monolayer structure, the first andsecond routing lines 156 and 186 may be formed to have a multilayerstructure, as exemplarily shown in FIGS. 7 and 8 . In this case, each ofthe first routing lines 156 may have a structure in which a firstrouting conductive layer 156 a and a second routing conductive layer 156b are stacked, and each of the second routing lines 186 may have astructure in which a first routing conductive layer (not shown) and asecond routing conductive layer (not shown) are stacked. Here, the firstrouting conductive layer 156 a is formed to have a monolayer ormultilayer structure using Al, Ti, Cu and Mo, and the second routingconductive layer 156 b is formed of ITO or IZO on the first routingconductive layer 156 a. Therefore, in case of each of the first andsecond routing lines 156 and 186, if cut of any one of the first andsecond routing conductive layers 156 a and 156 b occurs, the otherconductive layer transmits a touch driving pulse and a touch signal.

Further, although the above-described embodiments exemplarily illustratethat the bridges 152 b and the first touch electrodes 152 e of the touchdriving lines 152 are disposed on different planes and then connectedthrough the touch contact holes 150, bridges 154 b and second touchelectrodes 154 e of touch sensing lines 154 may be disposed on differentplanes and then connected through touch contact holes 150, asexemplarily shown in FIG. 9 . Further, although the present inventionexemplarily illustrates that the mutual capacitive touch sensors areformed between the touch sensing lines 154 and the touch driving lines152 intersecting each other, the present invention may be applied toself-capacitive touch sensors formed along touch lines formed in onedirection.

Moreover, although the embodiments shown in FIGS. 1, 7 and 8 exemplarilydescribe that the first and second touch electrodes 152 e and 154 e ofthe organic light emitting display are formed of a plate-typetransparent conductive film, i.e., the second conductive layer, thefirst and second touch electrodes 152 e and 154 e may be formed as amesh, as exemplarily shown in FIG. 9 . That is, each of the first andsecond touch electrodes 152 e and 154 e may include a transparentconductive film 1541 and a mesh metal film 1542 formed as a mesh on theupper or lower surface of the transparent conductive layer 1541.Otherwise, each of the touch electrodes 152 e and 154 e may include amesh metal film 1542 without a transparent conductive layer 1541, or thetransparent conductive layer 1541 may be formed as a mesh without a meshmetal film 1542. Here, the mesh metal film 1542 has higher conductivitythan the transparent conductive layer 1541 and may thus formlow-resistance electrodes as the touch electrodes 152 e and 154 e.Thereby, resistances and capacitances of the touch electrodes 152 e and154 e are reduced and a time constant RC is reduced, thus improvingtouch sensitivity. Further, the mesh metal film 1542 has a very thinline width and may thus prevent an aperture ratio and transmittance frombeing lowered due to the mesh metal film 1542. Further, the bridges 154b disposed on a plane differing from the touch electrodes 154 e may beprovided with a plurality of slits, as exemplarily shown in FIG. 9 . Theslit 151 of the at least one of the first and second bridges 152 b, 154b overlaps with the other one of the first and second bridges 154 b, 152b. Therefore, the bridges 154 b provided with the slits 151 may have asmaller area than bridges provided with no slits. Thereby, reflection ofexternal light by the bridges 154 b may be reduced and lowering ofvisibility may be prevented. Such bridges 154 b provided with the slits151 are formed of a transparent conductive film or an opaque conductivefilm. If the bridges 154 b are formed of an opaque conductive film, thebridges 154 b overlap the banks 128 and thus prevent lowering of anaperture ratio.

As apparent from the above description, an organic light emittingdisplay having a touch sensor in accordance with the present disclosureincludes a compensation film having a flat surface and formed to coverdams and thus minimizes a part generated by the dams, thereby beingcapable of preventing cut and short-circuit of routing lines. Further,the organic light emitting display in accordance with the presentinvention disposes touch electrodes directly on an encapsulation unitwithout an adhesive and thus does not require a separate attachmentprocess, thereby simplifying the overall process and reducingmanufacturing costs.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope of the inventions. Thus, it is intendedthat the present invention covers the modifications and variations ofthis invention provided they come within the scope of the appendedclaims and their equivalents.

What is claimed is:
 1. A display apparatus comprising: a substrateincluding an active area and a pad area; light emitting elementsarranged on the active area; touch pads arranged on the pad area; atleast one dam arranged between the active area and the pad area; anencapsulation unit arranged on the light emitting elements, theencapsulation unit including at least one inorganic encapsulation layerand at least one organic encapsulation layer; touch sensors arranged onthe encapsulation unit; routing lines that connect the touch sensors tothe touch pads, the routing lines disposed on the at least one inorganicencapsulation layer and the at least one dam; and a compensation filmarranged on the at least one inorganic encapsulation layer andoverlapping the at least one dam, wherein a first region of thecompensation film that overlaps the at least one dam has a firstthicknesses and a second region of the compensation film that isnon-overlapping with the at least one dam has a second thickness that isdifferent from the first thickness.
 2. The display apparatus accordingto claim 1, further comprising: a plurality of color filters arranged onthe encapsulation unit.
 3. The display apparatus according to claim 2,further comprising: a black matrix arranged between the plurality ofcolor filters, wherein the compensation film comprises: a firstcompensation film layer including a same material as the black matrix;and a second compensation film layer including a same material as atleast one of the plurality of color filters, the second compensationfilm arranged on the first compensation film layer.
 4. The displayapparatus according to claim 3, further comprising: a touch buffer filmarranged on the plurality of color filters, wherein the compensationfilm further comprises: a third compensation film layer including a samematerial as the touch buffer film, the third compensation film arrangedon the second compensation film layer.
 5. The display apparatusaccording to claim 2, further comprising: a touch buffer film arrangedon the encapsulation unit; and a black matrix arranged between theplurality of color filters, wherein the compensation film includes asame film as at least one of the plurality of color filters, the blackmatrix, the touch buffer film, or the at least one organic encapsulationlayer of the encapsulation unit.
 6. The display apparatus according toclaim 5, wherein a thickness of the compensation film in a region aboveat least one of the at least one dam is less than a thickness of thecompensation film in the region between the at least one dam and thelight emitting elements.
 7. The display apparatus according to claim 1,further comprising: a touch buffer film arranged on the encapsulationunit, wherein the compensation film includes a same film as the touchbuffer film, and is formed integrally with the touch buffer film.
 8. Thedisplay apparatus according to claim 7, wherein the first thickness isless than the second thickness.
 9. The display apparatus according toclaim 1, wherein: the routing lines intersect the at least one dam, therouting lines are arranged in the first region above the at least onedam and in a region between the at least one dam and the light emittingelements, and the compensation film contacts the routing lines.
 10. Thedisplay apparatus according to claim 1, wherein the touch sensorscomprise: first touch electrodes arranged in a first direction on theencapsulation unit, the first touch electrodes connected to each otherthrough first bridges; and second touch electrodes arranged in a seconddirection on the encapsulation unit, the second touch electrodesconnected to each other through second bridges, at least one of thefirst touch electrodes or the second touch electrodes comprises a meshmetal film arranged as a mesh, and a transparent conductive layerarranged on an upper surface and a lower surface of the mesh metal film.11. The display apparatus according to claim 10, wherein at least one ofthe first bridges or the second bridges has slits, the slits of the atleast one of the first bridges or the second bridges overlap other onesof the first bridges and the second bridges, at least one of the firstbridges or the second bridges includes a monolayer or multilayerstructure using at least one selected from a group consisting ofaluminum, titanium, copper, and molybdenum, and at least one of thefirst bridges or the second bridges is arranged at a positioncorresponding to a bank that defines an emission region of the lightemitting elements.
 12. The display apparatus according to claim 10,wherein each of the touch pads comprises a pad electrode arranged on asame layer as a source electrode and a drain electrode of a thin filmtransistor, wherein each of the touch pads further comprises a pad coverelectrode arranged on the pad electrode.
 13. The display apparatusaccording to claim 12, wherein: the pad electrodes include a samematerial as at least one of the routing lines and are connected to therouting lines; the pad cover electrodes include a same material as atleast one of the first touch electrodes or the second touch electrodes;and one of the pad electrodes and the pad cover electrodes includes amonolayer or multilayer structure using at least one selected from agroup consisting of aluminum, titanium, copper, and molybdenum.
 14. Thedisplay apparatus according to claim 1, wherein the compensation film isarranged between the touch pads and the organic encapsulation layer ofthe encapsulation unit and fills spaces between the at least one dam orat least a part of a space between the organic encapsulation layer ofthe encapsulation unit and the at least one dam.